Pilot pressure reducing valve assembly of axial plunger pump

Abstract

According to the pilot pressure reducing valve assembly of the axial plunger pump, high-pressure oil directly led into an outlet of the plunger pump enters the pilot pressure reducing valve assembly, pressure is reduced through the action of a valve element and a spring, and then pressure oil with the constant pressure value ranging from 3.0 MPa to 3.3 MPa is output; and secondary pressure oil with the pressure changing along with the control current is output through the electromagnetic proportional pressure reducing valve and used for controlling the swing angle of a swash plate of the plunger pump. According to the pilot pressure reducing valve assembly of the axial plunger pump, external pilot oil pumps can be reduced, pipeline arrangement is simple, the structure is simple, and the manufacturing cost is low.

Description

Technical Field

[0001] The invention belongs to the technical field of axial piston pumps, and in particular relates to a pilot pressure reducing valve assembly that realizes the power-varying function of an axial piston pump. Background Art

[0002] The axial piston pump converts mechanical energy into pressure energy to provide a power source for the hydraulic system. In actual operation, the external load on construction machinery is constantly changing. The hydraulic pump needs to adjust the output flow and pressure to adapt to the load changes. Therefore, a variable mechanism is needed to adjust the swash plate angle at any time to control the displacement output. However, the existing axial piston pump pilot pressure reducing valve assembly needs to be connected to an external pilot oil, and the pipeline layout is complicated, resulting in a complex structure of the entire pilot control pipeline and high manufacturing costs. Summary of the invention

[0003] The present invention provides an axial piston pump pilot pressure reducing valve assembly, which provides control pressure oil for the axial piston pump variable mechanism, has the advantages of reducing external oil sources, reducing pipeline layout, simple structure and cost saving.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] An axial piston pump pilot pressure reducing valve assembly includes a pilot valve body, a mounting seat, a spring, a spring seat, a valve core, a first screw plug, a second screw plug, an electromagnetic proportional pressure reducing valve, a screw, a throttle plug and a plum blossom plug:

[0006] One side surface A of the pilot valve body is provided with four screw mounting holes penetrating the valve body, as well as a third oil inlet flow channel and a first oil outlet flow channel; the four screw mounting holes penetrating the valve body are used to fix the entire axial piston pump pilot pressure reducing valve assembly and the piston pump body through a connecting piece; a fourth oil inlet flow channel and a second oil inlet flow channel are provided on the top surface B adjacent to the side surface A; a valve core and a first cock mounting hole, a second screw mounting hole and an electromagnetic pressure reducing valve mounting hole are provided on another side surface C adjacent to the side surface A from top to bottom; the first oil outlet flow channel and the electromagnetic pressure reducing valve mounting hole are connected;

[0007] On the other side surface A′ opposite to the side surface A of the pilot valve body, in addition to the four screw mounting holes penetrating the valve body, a first oil inlet flow channel, a second oil outlet flow channel and a third oil leakage flow channel are provided; on the bottom surface B′ opposite to the top surface B of the pilot valve body, a first oil leakage flow channel is provided; on the other side surface C′ opposite to the side surface C of the pilot valve body, a second oil leakage flow channel and a mounting seat hole are provided, the mounting seat hole and the first oil leakage flow channel are connected, the first oil leakage flow channel and the second oil leakage flow channel are connected, and the second oil leakage flow channel and the third oil leakage flow channel are connected;

[0008] Among them, the first oil inlet flow channel and the second oil inlet flow channel are connected, the second oil inlet flow channel is connected with the valve core and the first plug mounting hole, the valve core and the first plug mounting hole are connected with the third oil inlet flow channel, the third oil inlet flow channel is a step hole, the third oil inlet flow channel is connected with the fourth oil inlet flow channel, the fourth oil inlet flow channel is connected with the electromagnetic pressure reducing valve mounting hole, the electromagnetic pressure reducing valve mounting hole is connected with the first oil outlet flow channel, the second oil outlet flow channel and the third oil drain flow channel; the mounting seat is installed in the mounting seat hole of the side C' of the pilot valve body, and the mounting seat hole of the side C' is connected with the valve core and the first plug mounting hole of the side C; a second screw plug is installed at the step hole at the end of the third oil inlet flow channel and the second oil outlet flow channel respectively; the ends of the third oil inlet flow channel and the second oil outlet flow channel can be used as pressure measuring ports to connect external sensors to measure the pressure after decompression;

[0009] The mounting seat is threadedly connected to the mounting seat hole; a circular hole is provided inside the end of the mounting seat that contacts the spring for installing the spring; the end of the spring abuts against one end of the spring seat, and the other end of the spring seat is connected to the valve core, and the spring, spring seat, and valve core are all installed inside the valve core and the first plug mounting hole, and the valve core and the first plug mounting holes are step holes, and the ends are sealed by the first screw plug; the electromagnetic proportional pressure reducing valve is installed in the electromagnetic pressure reducing valve mounting hole on the side C of the pilot valve body, and is installed in the second screw mounting hole through a fastener, so that the electromagnetic proportional pressure reducing valve is installed on the pilot valve body; two plum blossom plugs are respectively installed on the step holes at the ends of the fourth oil inlet flow channel and the second oil inlet flow channel, and are used to seal the ends of the fourth oil inlet flow channel and the second oil inlet flow channel; the electromagnetic proportional pressure reducing valve is used to output secondary pressure oil whose pressure changes with current;

[0010] The throttle plug is installed on the stepped hole at the end of the first oil inlet channel on the side A′ of the pilot valve body 1 to play a throttling buffer role to prevent the incoming hydraulic oil pressure from being too high and impacting the valve core and the mounting seat.

[0011] Furthermore, the valve core is a stepped cylindrical structure, which is coaxially arranged by several cylinders with gradually increasing diameters from bottom to top. The spherical structure on one side of the valve core is connected to the spring seat. An oblong hole is opened inside the valve core for oil passing; the pressure on the valve core is balanced with the spring force.

[0012] Furthermore, there are two second screw mounting holes, which are symmetrically distributed on both sides of the electromagnetic pressure reducing valve mounting hole.

[0013] Furthermore, the second screw plug is a PF1 / 4 screw plug.

[0014] Furthermore, the first screw plug is a PF1 / 8 screw plug.

[0015] The beneficial effects of the present invention are as follows:

[0016] The axial piston pump pilot pressure reducing valve assembly of the present invention introduces high-pressure oil from the piston pump outlet through internal connection, reduces pressure after the action of the valve core and the spring to output a pressure oil with a fixed pressure value of 3.0-3.3MPa, and then after the pressure is reduced by the electromagnetic proportional pressure reducing valve, the output secondary pressure oil whose pressure changes with the control current acts on the variable mechanism to change the swash plate swing angle. The present invention can reduce the external oil source, reduce the pipeline layout, has a simple structure and low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A perspective view of an axial piston pump pilot pressure reducing valve assembly according to an embodiment of the present invention;

[0018] Figure 2 This is a cross-sectional view of the installation of the spring, spring seat, and valve core according to an embodiment of the present invention.

[0019] Figure 3 A perspective view of an axial piston pump pilot pressure reducing valve assembly from another perspective according to an embodiment of the present invention.

[0020] Figure 4 It is a three-dimensional diagram and a perspective diagram of one viewing angle of the pilot valve body 1 of the axial piston pump according to an embodiment of the present invention.

[0021] Figure 5 It is a three-dimensional diagram and a perspective diagram from another perspective of the axial piston pump pilot valve body 1 according to an embodiment of the present invention.

[0022] Figure 6 It is a circumferential side view of the valve core.

[0023] Figure 7 This is a side view of the electromagnetic proportional pressure reducing valve.

[0024] In the figure, 1, pilot valve body; 2, mounting seat; 3, spring; 4, spring seat; 5, valve core; 6, first screw plug; 7, second screw plug; 8, electromagnetic proportional pressure reducing valve; 9, M4 screw; 10, throttle plug; 11, plum blossom plug; 101, first oil outlet channel; third oil inlet channel 102; first screw mounting hole 103; 104, valve core and first cock mounting hole; 105, second screw mounting hole; 106, electromagnetic pressure reducing valve mounting hole; 107, second oil inlet channel; 108, fourth oil inlet channel; 109, first oil inlet channel; 110, first oil drain channel; 111, second oil drain channel; 112, third oil drain channel; 113, second oil outlet channel; 114, mounting seat hole. DETAILED DESCRIPTION

[0025] The present invention will be described in detail below based on the accompanying drawings and preferred embodiments, and the purpose and effects of the present invention will become more clear. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] like Figures 1 to 3 As shown, the axial piston pump pilot pressure reducing valve assembly of this embodiment includes a pilot valve body 1, a mounting seat 2, a spring 3, a spring seat 4, a valve core 5, a first plug screw 6, a second plug screw 7, an electromagnetic proportional pressure reducing valve 8, a screw 9, a throttling plug 10 and a plum blossom plug 11.

[0027] Among them, Figure 4 As shown, it is a three-dimensional diagram and a perspective view of the pilot valve body 1. One of the side surfaces A of the pilot valve body 1 is provided with four screw mounting holes 103 penetrating the valve body, as well as a third oil inlet channel 102 and a first oil outlet channel 101; the four screw mounting holes 103 penetrating the valve body are used to fix the entire axial piston pump pilot pressure reducing valve assembly and the piston pump body through a connecting piece; a fourth oil inlet channel 108 and a second oil inlet channel 107 are provided on the top surface B adjacent to the side surface A. The other side surface C adjacent to the side surface A is provided with a valve core and a first plug mounting hole 104, a second screw mounting hole 105 and an electromagnetic pressure reducing valve mounting hole 106 in sequence from top to bottom. And there are two second screw mounting holes 105, which are symmetrically distributed on both sides of the electromagnetic pressure reducing valve mounting hole 106. The first oil outlet channel 101 and the electromagnetic pressure reducing valve mounting hole 106 are connected.

[0028] like Figure 5 As shown, it is a three-dimensional diagram of the pilot valve body 1 from another perspective, which is exactly the same as Figure 4 Complementary. Figure 5 It can be seen that on the other side A' opposite to the side A of the pilot valve body 1, in addition to the four screw mounting holes 103 that penetrate the valve body, a first oil inlet channel 109, a second oil outlet channel 113 and a third oil leakage channel 112 are provided. A first oil leakage channel 110 is provided on the bottom surface B' opposite to the top surface B of the pilot valve body 1, and a second oil leakage channel 111 and a mounting seat hole 114 are provided on the other side C' opposite to the side C of the pilot valve body 1. The mounting seat hole 114 and the first oil leakage channel 110 are connected, the first oil leakage channel 110 and the second oil leakage channel 111 are connected, and the second oil leakage channel 111 and the third oil leakage channel 112 are connected.

[0029] Among them, the first oil inlet channel 109 is connected with the second oil inlet channel 107, the second oil inlet channel 107 is connected with the valve core and the first plug mounting hole 104, the valve core and the first plug mounting hole 104 are connected with the third oil inlet channel 102, the third oil inlet channel 102 is a step hole, the third oil inlet channel 102 is connected with the fourth oil inlet channel 108, the fourth oil inlet channel 108 is connected with the electromagnetic pressure reducing valve mounting hole 106, the electromagnetic pressure reducing valve mounting hole 106 is connected with the first oil outlet channel 101, the second oil outlet channel 113 and the third oil drain channel 112.

[0030] Back to Figure 1 and Figure 2 The mounting seat 2 is mounted in the mounting seat hole 114 of the side C' of the pilot valve body 1, and the mounting seat hole 114 of the side C' is connected with the valve core and the first plug mounting hole 104 of the side C. The step holes at the ends of the third oil inlet flow channel 102 and the second oil outlet flow channel 101 are respectively installed with a second screw plug 7, and the second screw plug 7 is a PF1 / 4 screw plug. The ends of the third oil inlet flow channel 102 and the second oil outlet flow channel 101 can be used as pressure measuring ports to connect external sensors to measure the pressure after decompression.

[0031] like Figure 1 As shown, the outer peripheral surface of the mounting seat 2 is provided with external threads for mating with the internal threads inside the mounting seat hole 114. Figure 2 As shown, a circular hole is provided inside the end of the mounting seat 2 that contacts the spring for mounting the spring 3. The end of the spring 3 abuts against one end of the spring seat 4, and the other end of the spring seat 4 is connected to the valve core 5. The spring 3, spring seat 4, and valve core 5 are all mounted inside the valve core and the first cock mounting hole 104. The valve core and the first cock mounting hole 104 are stepped holes, and the ends are sealed by the first screw plug 6. The first screw plug 6 is a PF1 / 8 screw plug. Figure 6 As shown, the valve core 5 is a stepped cylindrical structure, which is formed by coaxial arrangement of several cylinders with gradually increasing diameters from bottom to top. One side of the valve core 5 is a spherical structure connected to the spring seat 4. An oblong hole is opened inside the valve core 5 for oil to pass through. The pressure on the valve core 5 is balanced with the spring force.

[0032] Back to Figure 1 The electromagnetic proportional pressure reducing valve 8 is installed in the electromagnetic pressure reducing valve installation hole 106 on the side C of the pilot valve body 1, and is installed in the second screw installation hole 105 through two screws 9, so that the electromagnetic proportional pressure reducing valve 8 is installed on the pilot valve body 1. Two plum blossom plugs 11 are respectively installed on the step holes at the ends of the fourth oil inlet flow channel 108 and the second oil inlet flow channel 107, and are used to seal the ends of the fourth oil inlet flow channel 108 and the second oil inlet flow channel 107. The electromagnetic proportional pressure reducing valve 8 is used to output secondary pressure oil whose pressure changes with current, and the structure is as follows Figure 7 shown.

[0033] like Figure 3 As shown, the throttle plug 10 is installed on the stepped hole at the end of the first oil inlet channel 109 on the side A′ of the pilot valve body 1 to play a throttling buffer role to prevent the incoming hydraulic oil pressure from being too high and impacting the valve core 5 and the mounting seat 2.

[0034] The following describes the hydraulic oil circuit of the entire axial piston pump pilot pressure reducing valve assembly:

[0035] like Figure 1As shown in the red oil circuit, the high-pressure oil at the oil outlet of the plunger pump first enters the first oil inlet channel 109 through the throttle plug 10 on the side A′ of the pilot valve body 1, reaches the second oil inlet channel 107, and then reaches the valve core and the first plug mounting hole 104. The liquid pressure generated by the valve core 5 installed in the valve core and the first plug mounting hole 104 and the spring force in the mounting seat 2 are balanced to output a pressure oil with a fixed pressure value of 3.0 to 3.3 MPa. The pressure oil passes through the third oil inlet channel 102 and then through the fourth oil inlet channel 108 to reach the electromagnetic pressure reducing valve mounting hole 106. By adjusting the current of the electromagnetic proportional pressure reducing valve 8, the current changes from 0 to 750 mA, and the secondary pressure oil with the output pressure changing from 0 to 3.0 MPa flows out from the second oil outlet channel 113, acting on the variable mechanism on the plunger pump, thereby controlling the swash plate swing angle and changing the displacement output. At the same time, Figure 1 As shown in the blue oil circuit, when the hydraulic oil acts on the valve core, a small amount of oil leaks into the mounting seat hole 114, flows to the first oil leakage channel 110, and then flows to the third oil leakage channel 112 through the second oil leakage channel 111. At the same time, the oil leaked in the electromagnetic proportional pressure reducing valve 8 also flows out from the third oil leakage channel 112 to the inside of the plunger pump housing.

[0036] The first oil outlet channel 101 and the electromagnetic pressure reducing valve mounting hole 106 are connected. Since the step hole at the end of the first oil outlet channel 101 is sealed by the second screw plug 7, the oil in the first oil outlet channel 101 flows out through the electromagnetic pressure reducing valve mounting hole 106 and the second oil outlet channel 113.

[0037] The installation process of the axial piston pump pilot pressure reducing valve assembly of this embodiment is as follows:

[0038] The first screw plug 6, the second screw plug 7 and the plum blossom plug 11 are fixed to the pilot valve body 1 by threaded connection; install the valve core 5, and install the valve core 5 in the valve core and the first plug mounting hole 104, with the end of the valve core 5 with a spherical structure facing the mounting seat hole 114; put the spring 3 in the inner hole of the mounting seat 2, and then put the spring seat 4 on the spring 3, and finally install the three components together into the valve core and the first plug mounting hole 104, and the ball socket of the spring seat 4 and the spherical end of the valve core 5 are just in contact; install the electromagnetic proportional pressure reducing valve 8 in the electromagnetic pressure reducing valve mounting hole 106, and install two M4 screws 9 and tighten them; finally, install the throttling plug 10 in the first oil inlet channel 109.

[0039] The present invention can reduce external oil sources, reduce pipeline layout, and has a simple structure and low cost.

[0040] Those skilled in the art can understand that the above are only preferred examples of the invention and are not intended to limit the invention. Although the invention is described in detail with reference to the above examples, those skilled in the art can still modify the technical solutions recorded in the above examples or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, etc. made within the spirit and principle of the invention shall be included in the protection scope of the invention.

Claims

1. An axial piston pump pilot pressure reducing valve assembly, characterized in that: It comprises a pilot valve body (1), a mounting seat (2), a spring (3), a spring seat (4), a valve core (5), a first screw plug (6), a second screw plug (7), an electromagnetic proportional pressure reducing valve (8), a screw (9), a throttle plug (10) and a plum blossom plug (11): One side surface A of the pilot valve body (1) is provided with four screw mounting holes (103) penetrating the valve body, as well as a third oil inlet flow channel (102) and a first oil outlet flow channel (101); the four screw mounting holes (103) penetrating the valve body are used to fix the entire axial piston pump pilot pressure reducing valve assembly and the piston pump body through a connecting piece; a fourth oil inlet flow channel (108) and a second oil inlet flow channel (107) are provided on the top surface B adjacent to the side surface A; a valve core and a first cock mounting hole (104), a second screw mounting hole (105) and an electromagnetic pressure reducing valve mounting hole (106) are provided on another side surface C adjacent to the side surface A in order from top to bottom; the first oil outlet flow channel (101) and the electromagnetic pressure reducing valve mounting hole (106) are connected; On another side surface A' opposite to the side surface A of the pilot valve body, in addition to the four screw mounting holes (103) penetrating the valve body, a first oil inlet channel (109), a second oil outlet channel (113) and a third oil leakage channel (112) are provided; on a bottom surface B' opposite to the top surface B of the pilot valve body, a first oil leakage channel (110) is provided; on another side surface C' opposite to the side surface C of the pilot valve body, a second oil leakage channel (111) and a mounting seat hole (114) are provided, the mounting seat hole (114) and the first oil leakage channel (110) are connected, the first oil leakage channel (110) and the second oil leakage channel (111) are connected, and the second oil leakage channel (111) and the third oil leakage channel (112) are connected; The first oil inlet flow channel (109) is connected to the second oil inlet flow channel (107), the second oil inlet flow channel (107) is connected to the valve core and the first plug mounting hole (104), the valve core and the first plug mounting hole (104) are connected to the third oil inlet flow channel (102), the third oil inlet flow channel (102) is a stepped hole, the third oil inlet flow channel (102) is connected to the fourth oil inlet flow channel (108), the fourth oil inlet flow channel (108) is connected to the electromagnetic pressure reducing valve mounting hole (106), and the electromagnetic pressure reducing valve mounting hole (106) is connected to the first oil outlet flow channel (101). , the second oil outlet flow channel (113) and the third oil leakage flow channel (112) are connected; the mounting seat (2) is installed in the mounting seat hole (114) of the side C' of the pilot valve body (1), and the mounting seat hole (114) of the side C' is connected with the valve core and the first plug mounting hole (104) of the side C; a second screw plug 7 is installed at the step hole at the end of the third oil inlet flow channel (102) and the second oil outlet flow channel (101) respectively; the ends of the third oil inlet flow channel (102) and the second oil outlet flow channel (101) can be used as pressure measuring ports to connect external sensors to measure the pressure after decompression; The mounting seat (2) is threadedly connected to the mounting seat hole (114); a circular hole is provided inside the end of the mounting seat (2) that contacts the spring for mounting the spring (3); the end of the spring (3) abuts against one end of the spring seat (4); the other end of the spring seat (4) is connected to the valve core (5); the spring (3), the spring seat (4) and the valve core (5) are all mounted inside the valve core and the first plug mounting hole (104); the valve core and the first plug mounting hole (104) are stepped holes, and the ends are sealed by the first screw plug (6); the electromagnetic proportional pressure reducing valve (8) is mounted on the first The electromagnetic proportional pressure reducing valve (8) is installed in the electromagnetic pressure reducing valve installation hole (106) on the side C of the pilot valve body (1), and is installed in the second screw installation hole (105) through a fastener, so that the electromagnetic proportional pressure reducing valve (8) is installed on the pilot valve body (1); two plum blossom plugs (11) are respectively installed on the step holes at the ends of the fourth oil inlet flow channel (108) and the second oil inlet flow channel (107), and are used to seal the ends of the fourth oil inlet flow channel (108) and the second oil inlet flow channel (107); the electromagnetic proportional pressure reducing valve (8) is used to output secondary pressure oil whose pressure changes with current; The throttle plug (10) is installed on the stepped hole at the end of the first oil inlet channel (109) on the side A' of the pilot valve body 1, and is used to play a throttling buffer role to prevent the incoming hydraulic oil pressure from being too high and impacting the valve core (5) and the mounting seat (2).

2. The axial piston pump pilot pressure reducing valve assembly according to claim 1, characterized in that: The valve core (5) is a stepped cylindrical structure, which is formed by a plurality of cylinders coaxially arranged with diameters gradually increasing from bottom to top. The spherical structure on one side of the valve core (5) is connected to the spring seat (4). An oblong hole is provided inside the valve core (5) for oil to pass through. The pressure on the valve core (5) is balanced with the spring force.

3. The axial piston pump pilot pressure reducing valve assembly according to claim 1, characterized in that: There are two second screw mounting holes (105), which are symmetrically distributed on both sides of the electromagnetic pressure reducing valve mounting hole (106).

4. The axial piston pump pilot pressure reducing valve assembly according to claim 1, characterized in that: The second screw plug (7) is a PF1 / 4 screw plug.

5. The axial piston pump pilot pressure reducing valve assembly according to claim 1, characterized in that: The first screw plug (6) is a PF1 / 8 screw plug.

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